1. Field of the Invention
The present invention relates to a coupler for attaching an accessory, such an excavator bucket, to an excavator arm of an excavator. In particular, it relates to a fully automatic coupler for attachment, at its top half, to an excavator arm, and having, in its bottom half, two jaws and two latches for selectively securing (or releasing) two attachment pins of an accessory in (or from) the jaws of the coupler.
2. Description of Related Art
Many different couplers for attaching accessories to an excavator arm of an excavator have been developed. Many of those have been either manual or semi-automatic in function, i.e. requiring one or more manual steps to be carried out at the coupler in order to complete or commence the attachment or removal of an accessory onto or from the coupler. An increasing drive, however, is towards providing a fully automatic coupler. Such couplers allow the full securement and release procedure, i.e. for securing or releasing an accessory onto or from the coupler, by the operator from within the cab of the excavator, e.g. via controls provided in the cab.
There is also a further problem with couplers of this type—users occasionally use them incorrectly. Therefore, there is a further drive in the art to provide couplers that either prevent incorrect usage, or which counter incorrect usage by making such usage less dangerous by the provision of secondary or tertiary locking mechanisms, in addition to the primary locking mechanism provided by a latching hook, so as to provide mechanical back up mechanisms for preventing inadvertent release of the accessory from the coupler in the event of an improper use of the coupler.